1. Field of the Invention
The present invention relates to a patterned color conversion film (PCCF) and a display device using the same and, more particularly, to a patterned color conversion film prepared with quantum dots to replace conventional color filters and a display device using the same.
2. Description of Related Art
Quantum dots (QDs) are a kind of zero dimensional semiconducting nanocrystals, and the sizes thereof in each direction are all in nano-scales. As the sizes of the semiconductor particle decreased to nano-scales, the surface effect thereof induces QDs to have different physical and chemical properties from those of mass material. In addition, when the size of the particles is less than exciton Bohr radius, the bandgap thereof may be increased and the wavelength of the emitting light thereof may be shorten as the size thereof decreased. Hence, the wavelength of the emitting light of the quantum dots can be adjusted through changing the particle size thereof. In addition, the spectrum of the quantum dots can be reduced into fill width at half maximum (FWHM), which cannot be accomplished by conventional fluorescent materials or light-emitting materials. Recently, quantum dot/polymer complex has been widely applied to the backlight and lighting fields. For example, Nexxus Lighting has provided a quantum dot LED lighting, NNCrystal has developed a quantum dot platform Qshift, Nanosys has provided a quantum dot enhanced film (QDEF), and Nanoco has developed quantum dots without using Cd. Furthermore, complexes containing quantum dots with different light-emitting wavelength can convert single wavelength light emitting from a backlight source into light with various wavelengths. Hence, patterned color conversion films made of quantum dot complexes have potential to replace conventional color filters.
However, in the case that the color filters are substituted with patterned color conversion films made of quantum dot complexes, the backlight cannot be absorbed completely and color shifts and poor viewing angle characteristics may be occurred as the thickness of the patterned color conversion films is not thick enough. In order to absorb and convert the backlight completely, the thickness of the patterned color conversion films has to be increased. However, the films with increased thickness may cause material waste and increase the process complexity. Meanwhile, most of the light emitting from the quantum dots enters into a waveguide mode. Hence, when the patterned color conversion films was used as color filters, the light in the waveguide mode may be absorbed by black matrix thereof, which cause the light extraction rate of the film decreased.
Therefore, it is desirable to provide a patterned color conversion film, which has high backlight utilization rate and high light extraction rate without increasing the thickness thereof, and the problem of color shift thereof can also be solved, in order to replace the conventional color filters used in display devices.